Many critical UNIX systems have the highest availability requirements. These systems have the requirement of being constantly patched to the current level for operating systems to minimize the potential service outage due to a known issue. Patches are often released daily. Unfortunately, these two requirements are contradictory. Patching introduces downtime, often excessive downtime. Current patching state of the art also has weaknesses in the patch removal process, again introducing more downtime on systems that cannot tolerate it.
Eliminating downtime required for applying patches would be ideal but unobtainable due to the nature of the underlying UNIX based operating system and the fact that that many patches require downtime for a reboot. There is a need to minimize downtime to simply the boot time required for this most intrusive of operations.